What is the best way to debug a failed agent install (the first I have come across)? I have a PC in a remote office that won't let the 4.5 agent be installed and I wondered what the best way of debugging this was, as all the other PC's in that office installed the agent just fine.
Your first port of call should be the agent install logs - frminst_<machinename>.log, and in the case of MA4 and above, MFEAgent.msi.log. The location of these files can vary depending on how the insall was done - you may need to search the machine for them. (They will most likely be in the user or system %temp% folders, in a folder called McAfeeLogs.)